Ok, so as of last night my car has been venting funny. It builds boost normally, there seems to be no difference on the exhaust side, but my boost gauge isn't quite as responsive and my BoV vents weakly. It's more of a "Puuush" than the "Psht!" it used to be. When it was working properly even in -Hg it'd vent with an assertive sneeze, whereas now it sounds almost like it's wheezing the compressed air out. I'm hearing a bit of a second whistle on turbo spool as well which leads me to believe I have a boost leak. Any thoughts, suggestions or other possible diagnosis?

Vince's suggestion so far: Take apart the BoV and check the spring.

I'll prolly do that Saturday, but in the meantime I've checked hoses and piping connections and everything seems kosher. I dunno...I'm stumped for the time being.

Feel free to ask questions and give suggestions. Hopefully one of our resident boost gurus will chime in.

 

Either try 2 things, tighten BOV, or borrow a friends to have a go..

The Spring rate in bovs should be tight, but as your running 5 pound, i wouldnt do it too tight otherwise it won't vent..

Also, have you checked your intercooler pipes ? sometimes the rubber can create a crack ( even if they are new), we just came across this problem on a car here.. other then that..

I dunno

 

Well both fortunately and unfortunately i think i may have found the root of the problem (and possibly all my boost problems).

One of the bolts holding my manifold to the head (bottom row, second from the left) has snapped off and MAY be causing an exhaust leak. Now this might explain some or all of my boost holding problems. Oddly enough She still spools decently and I still start spooling at 2,250rpms. God only knows how long that's been broken or whether the heat has eaten through the gasket.

I'm still checking for boost leaks though because of the weird venting sound and I guess I'm going to have to see if the folks down at BM Tranny will be able to do any emergency servicing for me. **** all. I have absolutely no luck with this friggin' car.

 

I told you so. didnt i say gasket? sucks man

 

Yeah, but it still doesn't make sense why it hasn't effected spool, and why it only started making the funny venting sound last night. Seems like two separate failures to me. With my luck it's probably 9.

 

Took apart the BoV tonight. Aside from being slightly dirty it seems to be ok.

So here are the four main possibilities:

1. BoV opening too soon. This one's unlikely due to my low boost levels and I would imagine I'd have had problems with it before now if it were the cause.

2. Random leak in a vac hose or piping connector. Very possible. I have about 40,000 some odd taps on my vac lines and my IC piping isn't what you would call permanent.

3. Wastegate opening prematurely. Always a possibility considering I've had problems maintaining boost since day 1.

4. The aforementioned broken bolt which may or may not actually be leaking exhaust. I can't tell because it's certainly not visible, but last I checked there seemed to be a slight bit of condensation around it so it's a strong possibility as well.

Then there's always the possibility it's a combination of two or more of any of the above. Anymore suggestions, tips etc? I've gotten all of three so far from only three people.

 

Sell it, Move to Australia and buy a modifed GSR Lancer

Apart from that, my boost leak is my BOV Spring.. i just bought a new one just then

 

hey hobie try and run a vacume pressure test on your signal line that power your bov and stuff check it it should eb around 18 unless its leaking

other thing maybe did you ever take off your tb? you might have damaged the gasket and could be leaking out of there
let me know what happens or if you find anythign else

 

I highly doubt your possible exhaust leak at the head is doing anything to the boost. I left the lower left nut off mine and it leaked and there was no question that it was leaking, exhaust leaks at the head are loud, like really really loud. Event though it was leaking it didnt affect the turbo performance it just ate the corner off the gasket.

I dont know about the wastegate. The only thing to go wrong with them is to be stuck open(partially or all the way) or closed. DeltaGates are supposedly POS (I have one too) and they take on extreme amounts of heat making them a likely canidate for failure. I have a Tial laying here that is stuck open like 1/8". I was using it before knew it was AFU and I couldn't build boost to save my life. But you say you are building boost normally so I think that can be ruled out.

BOV or Vac leak, it has to be. What are you using to feed your BOV? I used the fitting on the compressor housing to feed the wastegate and BOV. Prior to that I was hooked onto the intake manifold and the BOV worked fine, but was kinda lame, hooked directly to the compressor it seemed to be a lot more crisp when it vented.

 

My car is always loud and always stinky so it still may be a minor exhaust leak at the head. Anyway, I'm going to order all new silicone couplings, clamps and coolant/vac hoses in the near future.

Recently boost seems a bit more sluggish, but I may just be looking too much into it or something...I dunno. BoV I believe is being fed off the vac line on top of the valve cover. I've got more vac lines under my hood than God knows what.

Thanks for the help, guys. I'll keep you posted, but I hardly have a moment to breathe, much less work on my car, so it may be some time before I have this resolved.